D-mannose is a type of sugar that is related to glucose, but it does not behave like sugar in the body. It is used to help prevent urinary tract infections because it inhibits bacteria from adhering to the walls of the urinary tract. If bacteria can’t latch onto your bladder, it’s less likely to cause an infection.

Some people are prone to getting repeated bladder infections; D-mannose can greatly improve quality of life and reduce reliance on antibiotics. Although antibiotics are sometimes necessary, they can have very detrimental effects on your immune system. Preventing an infection in the first place is a much healthier option.

D-mannose is a natural molecule that is found in cranberries, apples and some other fruits. It is the active ingredient in cranberries, minus the sugar that usually accompanies cranberry products like juice. If you have a bladder infection, sugar is the last thing you should consume because it can encourage the growth of harmful bugs and fuel an infection.

Apart from D-mannose, the other beneficial component of cranberries is a type of antioxidant called proanthocyanidins. These types of antioxidants were first identified in pine bark and grape seeds, but they are also very concentrated in cranberries. They have also been found to reduce the ability of bacteria to adhere to the urinary tract.

Urinary tract infections (UTIs) are a very common health problem in the USA, affecting more than 20 million Americans each year. Women are far more prone to these infections than men. The most common symptoms of a UTI are urinary frequency, urgency and burning pain on urination. Interestingly, the symptoms of a UTI in men are usually a lot milder, and in fact sometimes men can experience no symptoms at all, so they’re unaware of the infection. UTIs in men can inflame the prostate gland and cause chronic prostate problems.

Menopausal women are at high risk of getting a UTI because the loss of estrogen causes thinning of the tissue of the bladder and urethra. A thinner lining is more prone to infection with bacteria.

How do bacteria cause a urinary tract infection?

Most cases of UTIs are caused by the bacteria E. coli. This bacteria is normally present inside the digestive tract and on the skin surrounding the anus. In women, it is easier for the bacteria to travel to the urethra because the urethral opening is a lot closer to the anus than in men.

In order to cause an infection, bacteria must first adhere to the cells lining the urinary tract. They do this using hair-like fimbriae that protrude from their surfaces. The fimbriae attach to specific receptors on your cells. D-mannose helps to prevent infections by interfering with the ability of the fimbriae to latch onto your cells.

Other recommendations for preventing urinary tract infections

  • After you have a bowel motion, make sure you wipe from front to back, to avoid spreading bacteria toward your urethra.
  • Women should urinate after sexual intercourse.
  • Drink 8 to 10 glasses of water or herbal tea each day, to keep the urine dilute and to flush the walls of the urinary tract. Increase your water intake during an infection. This helps to reduce the risk of the infection travelling upwards to the kidneys.
  • Try to eat lots of fresh vegetables and fruit each day, as they contain nutrients to strengthen your immune system, as well as antioxidants to keep the lining of your urinary tract healthy. Incorporating raw vegetable juices into your diet will provide even more benefits.
  • Try to avoid sugar and refined carbohydrates that are rapidly digested into sugar. This includes foods like bread, pasta and breakfast cereals. Diabetics are prone to all sorts of infections; this is because sugar acts like a fertiliser for harmful microbes in your body.
  • Caffeine and alcohol can irritate the bladder. Keep your intake of them low, and avoid them entirely if you have an infection.
  • Probiotics help to keep your urinary tract healthy by discouraging the proliferation of harmful microbes. You can take a probiotic supplement or include fermented foods in your diet regularly, such as sauerkraut, kefir and kombucha.
  • Selenium is a mineral that many people don’t get enough of in their diet because not many foods are a rich source. Selenium helps to strengthen the immune system and reduces the risk of infections.

How to take D-mannose

D-mannose is best taken on an empty stomach. Take 1 or 2 capsules daily, to help prevent urinary tract infections. D-mannose is safe for long term use.

If you have the symptoms of a urinary tract infection for more than 2 days please see your doctor. Mild cases can often be overcome with the above suggestions, but sometimes antibiotics are necessary.


The above statements have not been evaluated by the FDA and are not intended to diagnose, treat or cure any disease.